The instant invention finds particular application in the field of locating and surveying concealed structures.
More broadly, the invention finds application for positional, or other value indicative, measurement of the magnitude of at least two input signals and producing therefrom a directly derived signification as to the magnitude of each respective input signal as well as the measure of deviation between the individual input signal values.
The effective result is an output pattern of directly derived pulse train periodicities, or else binary code values, representative of each of several input signal levels.
Prior teachings have shown the artisian several ways to achieve, by indirect deriviation, audio frequency output signals from concealed object detectors which are in part proportional to the amplitude of an inputted signal as might be induced by an electromagnetic field emanating from a concealed structure or the like. A particularly accomplished such teaching appears in U.S. Pat. No. 4,044,299, Weber: "Concealed Structure Locating and Surveying Translator Apparatus".
More advanced teachings by Weber in U.S. Pat. No. 4,147,973 "Frequency Dependent Amplitude Modulated Translator Apparatus" is given wherein an audio frequency rate periodic monophonic output signal is produced as a direct deriviative of the special modulating waveform produced by an efficacious exciter such as described by Weber in U.S. Pat. No. 4,137,500 "Frequency Dependent Amplitude Modulated Exciter Apparatus". The prior work by Weber and others is not anticipative of the effectual use of more than one inducer, or input means, nor more than one, say monophonic, output signal means.
The essence of the present invention is therefore to:
provide at least two input signal input terminal means; PA1 provide at least two output signification responser means; PA1 provide a stereophonic-like, or else multiphonic, output indication to a human operator thereof primarily for purpose of RIGHT or LEFT positional relationship; PA1 provide a binary code signal therefrom the encoded value of which gives weight to each of the several input signal levels; PA1 and, most importantly all the aforesaid improvements are taught making the most effective use of the input signal values as to produce an effectively stable, meaningful signal output therefrom which may be used and adjusted by operators of minimal skill; PA1 and furthermore, the taught apparatus employs a minimum of low cost elements to attain the desired result, using a minimum of power thereby extending the practical life of batteries or the like when portable operation of the combination is necessary.